This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present invention, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present invention. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
As will be appreciated, supplies of oil and natural gas have a profound effect on modern economies and civilizations. Devices and systems that depend on oil and natural gas are ubiquitous. For instance, oil and natural gas are used for fuel in a wide variety of vehicles, such as cars, airplanes, boats, and the like. Further, oil and natural gas are frequently used to heat homes during winter, to generate electricity, and to manufacture an astonishing array of everyday products.
In order to meet the demand for these resources, companies often spend a significant amount of time and money searching for and extracting oil, natural gas, and other subterranean resources from the earth. Particularly, once a desired resource is discovered below the surface of the earth, a drilling system is often employed to access and extract the resource. These drilling systems may be located onshore or offshore depending on the location of a desired resource. Further, such systems include a wide array of components, such as valves, that control drilling or extraction operations. Often, some of these components are controlled through pressure variation, such as that provided by a hydraulic control system.
As may be appreciated, hydraulic systems often include accumulator bottles that facilitate operation of the system. Generally, these accumulator bottles may be used to store pressurized hydraulic fluid in a hydraulic circuit; the accumulator bottle typically receives hydraulic fluid from the circuit in low-demand periods and returns the hydraulic fluid to the circuit as needed to supplement flow and pressure within the system. In many instances, a typical accumulator bottle will include a first chamber that communicates with the hydraulic circuit and a second chamber that contains a pressurized gas. As will be appreciated, the pressure setting of the gas is known as a “pre-charge”, and generally controls the amount of energy which may be stored by the accumulator bottle. Excessive pre-charge pressure may prevent the accumulator bottle from receiving hydraulic fluid, while insufficient pressure may not provide enough energy to force such fluid back into the hydraulic circuit when needed. Further, the amount of pre-charge desired generally depends on the ambient pressure in which the accumulator bottle is intended to operate. Consequently, movement of a typical accumulator bottle from one ambient pressure to another (e.g., between different operational depths) would often necessitate an adjustment to the pre-charge.